Methods and devices for making cups and similar vessels of a thermoplastic material



1955 J. H. G. OLLIER ETAL 7 METHQDS AND DEVICES FOR MAKING CUPS AND SIMILAR VESSELS OF A THERMOPLASTIC MATERI AL Filed Jan. 16, 1963 United States Patent METHQDS AND DEVICES F611 MAKING CUPS AND SIMZLAR VESSELS @F A THERMOPLASTIC MATERIAL Jacques Honor Gaspard Gllier, 17 rue General Hem-ion Bertier, Neuilly-sur-Seine, France; Georges Frdric Grosshans, 53 bis rue de Boulainvilliers, ?aris, France; and Robert Gaston Masson, 6 Blvd. de Courbevoie, Neuiliy-sur-Seine, France Filed Jan. 16, 1963, Ser. No. 251,822 Claims priority, application France, Feb. 1, 1962, 886,671 3 Claims. (Cl. 118-19) The present invention relates to the manufacture of cups or other vessels of a plastic material i.e. a material which is deformable when heated, such as polyethylene, polyvinyl chloride, and so on. This invention is more especially, but not exclusively, concerned with the manufacture of vessels, such as cups, intended to be piled up, in particular in automatic drink distributing apparatus.

The chief object of our invention is to provide a device of the above mentioned kind which is adapted to meet the requirements of practice, in particular concerning the facility of operation and the reduced cost of such vessels.

According to our invention the cup or other vessel is formed from a sheet of thermoplastic material which is previously softened by heating and this method comprises shaping this sheet into the form of a vessel having, just above the bottom thereof, a reduced cross section, the vessel wall between said section and said bottom comprising a flaring portion immediately beyond said reduced cross section, and a cylindrical portion between said flaring portion and said bottom, and folding back said cylindrical portion along said flaring portion so that said bottom is brought back substantially at the level of said reduced cross section.

The present invention is more especially concerned with the application to machines of the type described in the French Patent No. 1,180,058, of June 29, 1957.

A preferred embodiment of our invention will be hereinafter described with reference to the appended drawings, given merely by way of example, and in which:

FIG. 1 is an end view, with parts in section, of a device for manufacturing vessels according to our invention;

FIG. 2 shows on an enlarged scale a portion of the device of FIG. 1;

FIGS. 3 and 4 are half sections respectively illustrating two steps of the manufacture of a vessel made according to the present invention;

FIG. 5 shows the piling up of several vessels according to the invention.

The device of the present invention is intended to form a cup or similar vessel from a sheet or strip of thermoplastic material 1, previously softened by heating and it comprises a mould 2 carried by a support 3 movable vertically with a translatory motion along columns 5 by means of hydraulic jacks 5. The fixed upper portions 5 of these jacks are carried by a cross member '7 on which are also fixed the upper ends of columns 4. A punch 8 is carried by the moving rod 9 of a jack 1% so as to push sheet 1 into mould 2 (FIGS. 1 and 2).

The lower portion of the inner wall of mould 2 is provided with a peripheral inward projection 11 which makes an acute angle i with the axis of the mould, as shown by the drawing.

A counter-punch 12, carried by the movable rod 13 of jack 14 and located in the open bottom of mould 2, comprises a frusto-conical head 15 the taper half angle j of which is substantially equal to angle 1'.

Furthermore, cross member 7 carries a box shaped element 16 in line with mould 2, and the rod 9 of punch Patented Nov. 2, 1965 "ice 8 extends through the top wall 17 of said box 16. A conduit 18 makes it possible to blow compressed air into box 16.

The operation of this device (shown by FIGS. 1 and 2) is as follows:

Initially mould 2, punch 8 and counter-punch 12 are in positions remote from the plane of sheet 1.

Jacks 5 are actuated so as to move support 3, together with the mould 2 it carries, upwardly (i.e. in the direction of arrow F Thus the upper edge 19 of the mould applies sheet 1, previously softened by heating, against the lower surface 20 of box shaped element 16. The above mentioned parts then occupy the position shown by FIG. 1.

Jack 14 is at this time in a position such that counterpunch 12 is located as shown by FIG. 3. Punch 8 is then lowered (in the direction of arrow F so as to deform sheet 1 by stamping. Furthermore, the blowing of air (in the direction of arrow f through conduit 18 applies sheet 1 against the inner wall of mould 2 and gives it the shape of a vessel 1a provided with an inner projection 11:: at the level of the inner projection 11 of mould 2 (FIG. 3);

Jack 14 is then operated to move counter-punch 12 upwardly (i.e. in the direction of arrow F so as to fold back the bottom 21 of vessel 1a. Angles i and 1' enable the thermoplastic material to slide along the head 15 of counter-punch 12 to form the bottom of the vessel (FIG. 4). Furthermore, the pressure of compressed air, maintained during this step of the operation, keeps the thermoplastic material applied against the walls of mould 2 and counter-punch 12. At the end of the upward stroke of said counter-punch 12 the cooperating conical portions 22a and 22b of counter-punch 12 and mould 2, respectively, strongly compress between them the peripheral strips 22. of vessel in, forming a kind of peripheral foot or support on which the vessel can stand.

Finally, removal from the mould is obtained by actuating jacks 14, 10 and 5 successively, so as to move counterpunch 12 downwardly (in the direction of arrow F punch 8 upwardly (in the direction of arrow F and mould 2 downwardly (in the direction of arrow F It then suiiices to move the thermoplastic strip 1 one step forward or to replace it by another one, to be able to perform a new operation of the machine.

The respective steps of the operation may be controlled either manually or by means of an automatic program.

There is thus obtained vessels which can be stacked as shown by FIG. 5. It has been found that due to the special shape of the bottom, the vessels are in contact with one another only along their supports 22, which facilitates their removal.

The device above described has, over similar devices, many advantages and in particular the following ones:

First, it works easily without consuming a great amount of energy.

Its cycle of operation may be made automatic so that the rate of manufacture is very high.

It may be adapted to existing machines for treating thermoplastic strips.

The vessels that are obtained have a very good balance.

These vessels are easily stacked and removed from a stack.

In a general manner, while we have, in the above description, disclosed what we deem to be a practical and eiiicient embodiment of the invention, it should be well understood that we do not wish to be limited thereto as there might be changes made in the arrangement, disposition and form of the parts without departing from the principle of the present invention within the scope of the appended claims.

What We claim is:

1. Apparatus for making a cup from a sheet of thermoplastic material previously softened by heating, comprising a mould defining a recess having a vertical axis and open at both ends, a hollow inverted box shaped element disposed above the mould, the lower margin of the box shaped element and the upper margin of the mould having coacting surfaces for holding a sheet of material during moulding, said mould having an inwardly downwardly tapered inner wall terminating at its lower end in an annular inwardly directed projection having an upper surface extending in a horizontal plane and having an outwardly downwardly extending annular lower surface, a punch positioned within said box shaped element above a sheet of material and movable along said vertical axis with respect to the mould to initiate formation of a cup, means for introducing fluid under pressure to the interior of the box shaped element for formation of a cup, a counter punch including an annular peripheral outwardly downwardly tapered surface complementary to and overlapping the lower surface of the inward projection of the mould, said counter punch being movable along said vertical axis with respect to the mould for folding back a double thickness of said material at the bottom of a cup and pressing said double thickness of 25 material against the lower surface of the inward projec- 4 tion to provide a cup having a downwardly outwardly tapered annular support.

2. The invention as defined in claim 1, wherein relative movement of the counter punch with respect to the mould is limited in one direction by the inward projection of the mould.

3. The invention as defined in claim 2, wherein the upper surface of the counter punch extends in a horizontal plane disposed at the limit of said movement in horizontal alignment with the upper surface of the inward projection, whereby a cup is formed having an inner bottom surface extending in a smooth horizontal plane.

References Cited by the Examiner UNITED STATES PATENTS 2,531,539 11/50 Smith 18-19 2,805,790 9/57 Smucker 22097 2,879,917 3/59 Flack 22097 3,004,285 10/61 Hagen 26498 3,050,773 8/62 Hagen 26498 3,105,270 10/63 Fibish 13l9 3,121,916 2/64 Edwards 1819 WILLIAM J. STEPHENSON, Primary Examiner.

ALEX NDER H. BRODMERKEL, Examiner. 

1. APPARATUS FOR MAKING A CUP FROM A SHEET OF TERMOPLASTIC MATERIAL PREVIOUSLY SOFTENED BY HEATING, COMPRISING A MOULD DEFINING A RECESS HAVING A VERTICAL AXIS AND OPEN AT BOTH ENDS, A HOLLOW INVERTED BOX SHAPED ELEMENT DISPOSED ABOVE THE MOULD, THE LOWER MARGIN OF THE BOX SHAPED ELEMENT AND THE UPPER MARGIN OF THE MOULD HAVING COACTING SURFACES FOR HOLDING S SHEET OF MATERIAL DURING MOULDING, SAID MOULD HAVING AN INWARDLY DOWNWARDLY TAPERED INNER WALL TERMINATING AT ITS LOWER END IN AN ANNULAR INWARDLY DIRECTED PROJECTION HAVING AN UPPER SURFACE EXTENDING IN A HORIZONTAL PLANE AND HAVING AN OUTWARDLY DOWNWARDLY EXTENDING ANNULAR LOWER SURFACE, A PUNCH POSITIONED WITHIN SAID BOX SHAPED ELEMENT ABOVE A SHEET OF MATERIAL AND MOVABLE ALONG SAID VERTICAL AXIS WITH RESPECT TO THE MOULD TO INITIATE FORMATION OF A CUP, MEANS FOR INTRODUCING FLUID UNDER PRESSURE TO THE INTERIOR OF THE BOX SHAPED ELEMENT FOR FORMATION OF A CUP, A COUNTER PUNCH INCLUDING AN ANNULAR PERIPHERAL OUTWARDLY DOWNWARDLY TAPERED SURFACE COMPLEMENTARY TO AND OVERLAPPING THE LOWER SURFACE OF THE INWARD PROJECTION OF THE MOULD, SAID COUNTER PUNCH BEING MOVABLE ALONG SAID VERTICAL AXIS WITH RESPECT TO THE MOULD FOR FOLDING BACK A DOUBLE THICKNESS OF SAID MATERIAL AT THE BOTTOM OF A CUP AND PRESSING SAID DOUBLE THICKNESS OF MATERIAL AGAINST THE LOWER SURFACE OF THE INWARD PROJECTION TO PROVIDE A CUP HAVING A DOWNWARDLY OUTWARDLY TAPERED ANNULAR SUPPORT. 